05/24/2008, Tucson AZ
24 May 2008 8:00pm through 11:37pm MST
(25 May 2008 03:00 through 06:37 UT)
Seeing: P. 4
Transparency: (NELM) 6.5 (SQM) 21.20
Weather: clear, cool, and a bit breezy.
Instrument: SVP8EQ
Eyepiece/filter list: 5mm Stratus; 9.5mm Lanthanum; 21mm Stratus.
Finally had my schedule and clear weather line up for a night at TIMPA. Unfortunately, the club scheduled TIMPA (again) on a night when the Moon was set to rise well before midnight. On a night when astronomical twilight did not end until a couple of minutes before 9pm local, that's not so good. Especially for an observer who works as slowly as yours truly.
While waiting for true darkness to settle over the breezy Arizona desert I spent a considerable amount of time observing Saturn. I turned the Newt up at the ringed world as soon as I could detect it in the twilight, then watched it gradually emerge from the brightness of the sky. I've never done this with a planet before that I can recall. The seeing was not the best for planetary observing (A3, if I were to be generous) but enough calm moments came, and enough lasted long enough, that I was quite happy with my views of Saturn. I used the 5mm Stratus again, and as I suspected from the brief use of this eyepiece on Saturn at CSP, this one really shows Saturn quite well. I was able to see the Cassini Division without trouble, even when the image was less than perfect. The ring shadow (or the contrast line between the ring and the planet, more likely) was visible, as was a dusky band on the planet and a darkening of the pole turned toward me. Four satellites were easily picked out with the Newt, mostly because of an unusual alignment. Titan was, of course, obvious, of to the east, but three moons I normally might miss against the starry night were conveniently arranged just to the west of the rings: Tethys, Dione, and Rhea from east to west. I may have waited a while for true darkness to settle in, but the time was surely well-spent.
Not long after 9pm local I tracked down and observed the globular cluster M53. The references I have describe this globular as being noticeably brighter in the center, which to my mind conjures a halo-core arrangement, which I did not see. The center was quite bright, no matter which eyepiece I used, but the increase was general, without a distinct core. The cluster overall was quite bright. In the 9.5mm Lanthanum it was not quite perfectly round, a bright hazy ball with a trio of what I assume were foreground stars that seemed to sparkle as I moved from direct to averted vision. I switched to the 5mm Stratus and was pleasantly surprised to how well the globular cluster handled magnification. The outer edge became rougher and more ragged. The probable foreground stars became visible to direct vision, and in averted vision the grainy appearance of the cluster glittered with stars, mostly at the edge of resolution, but a few consistently visible. M53 is a very attractive and rewarding object, and one to which I will return.
The galaxy M109 was a different matter altogether, being a much more subtle object. Locating this galaxy was no challenge, given its proximity to gamma Ursa Majoris. Observing M109 was a something of a challenge, due to its proximity to gamma Ursa Majoris. Unless I was careful to exclude gamma UMa from the field of view, the galaxy did not stand out clearly. Exclusion of the bright star was best accomplished by increasing magnification, which I did until I found the 9.5mm Lanthanum eyepiece gave me the best view. It was something of a compromise; this galaxy did not seem to take magnification as well as some other Messier galaxies do. It presented an elongated, pale glow that brightened slightly toward the center, but without an especially distinct core.
I made yet another attempt to split 38 Lyncis. This double is well within the range of the Newt, and yet past attempts have fallen short due to poor seeing conditions. The conditions tonight were not exactly fantastic, but good enough that I went for it. I came close. The star was somewhat oblong, and in steady moments the companion would just barely flicker into view as a separate entity. But these moments never lasted long enough to mark it as done, much less to let me observe the characteristics of the stars involved. So I left it, again, for a better night.
By this point my time was running out, with moonrise due within half an hour. There was another Messier galaxy I wanted to track down, the face-on spiral M83, in Hydra. One thing TIMPA offers that CSP lacks is a good, dark view of the southern sky (and it is this that will keep me from completely abandoning the idea of observing there). As an observing experience, it could not have been more different from M109, earlier in the evening. I once again settled on the 9.5mm Lanthanum as the most workable eyepiece, and settled in to see what I could see. The overall impression was one of a hazy, round glow with a distinctly brighter pip at the center. From this brighter core outward the glow had a somewhat patchy look to it, an impression that was fleeting but definite, depending on how I 'worked' my averted vision. I can't help wondering if the inconsistent brightness was a hint of spiral structure coming through. It was a bit like looking at M51 on a night with less than perfect transparency. The outer edge faded away into the darkness without a definite boundary, and effect I was unable to replicate in my sketch however lightly I touched the blending stump to the paper. It was a pleasant sight on which to end a brief observing session, and all by itself left me with a feeling of accomplishment. Add to it M109 and the very nice look I had of M53, and it was not a bad outing at all.
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04/12/2008, Tucson AZ
Seeing: Antoniadi 2 to 3
Transparency: (NELM) n/a (SQM) n/a
Weather: cool with a light breeze.
Instrument: 102mm Celestron WideView Refractor
Eyepiece/filter list: 4mm University Optics orthoscopic; V block filter.
Time for another evening with Ralph and the Moon, in the hope of covering a few of the required observations for the AL Lunar II club. I've decided to do the entire project with the all-purpose refractor, taking advantage of this new 'grab-and-go' option to catch features on clear nights when setting up the Newt is not practical. (And it surely would be foolish to set up the big guy when I'd only have time to describe a single crater.)
It promised to be a pleasant evening, even if the seeing conditions were not going to be the best. The day had been windy, with a weather system passing by to the north. At first glance I feared it would all be a waste of time; A2 isn't exactly average seeing, which had been predicted for the night. But it can change as the evening goes on, and this time patience paid off, with the air steadying down to A3 and making some good observations possible.
After the usual long look at the whole Moon, and double checking that the VMA's placement of the terminator with the evening's reality. I plan a session by spotting features from the AL list along the terminator, trying to pick those that will have a combination of light angle and shadows that shows them off well. I guide my selection of objects using the VMA's own "terminator list." The closer to the terminator a feature sits, however, the chancier an observation becomes. The VMA accurately places the terminator for the hour I intend to begin, but does not reveal the interplay of shadow and light in any real detail. As a result, features that on the map seem well placed may actually be difficult (or impossible) to observe. And in fact, from tonight's worksheet of eight possible targets, I observed only four (but counted only three for the AL Lunar II). The rest were caught up in shadows cast by objects just west of the darkness line. After tonight the way I use the VMA will change slightly, with less reliance being placed on its terminator list.
The first target of the night was the crater Cassini. Of the features I observed tonight, it probably sat in the best position relative to the terminator. The eastern rim of the crater cast a slim, smooth curve of shadow part way around the crater floor, extending just about half way to Cassini A. The western arc of the rim, in contrast, cast a longer shadow out into the eastern Mare Imbrium, ragged and spiky where the other had been smooth. The high ground just beyond Cassini's west rim caught some sunshine, creating a slim highlight within the base of the ragged shadow, and giving the illusory impression that the shadow had become detached from the crater. Of the interior craters (they seem too large relative to Cassini itself to warrant the term 'craterlet') Cassini A was especially prominent, and mostly filled with shadow; the inner face of its west wall was especially bright in contrast with the shadow it cast out into Cassini. Cassini B was also mostly shadow filled, but the inner face of its west wall was not especially brilliant. The crater rim did, however, cast a shadow that nearly closed the narrow gap between Cassini B and the west wall of the main crater. The crescent-shaped apron of debris that hugs the outer face of the eastern wall was clearly visible this time, as was the somewhat jumbled terrain around to the north containing Cassini M and Cassini W. The south wall of Cassini proper had an insubstantial look, thin and, in places, almost invisible where it met the mare material just beyond.
In the vicinity of Cassini, Mons Blanc and the Promontoria DeVille and Agassiz caught my eye with especially dramatic combinations of bright peaks and bold shadows.
As I was taking notes regarding Cassini and its vicinity I noticed a peculiar pulsing quality to the already dicey seeing conditions. On a hunch I switched off the clock drive; the effects of the seeing conditions were reduced to the usually shimmer. The scope was not properly balanced for the angle at which it was set, a difficult thing to remedy since this refractor is too short to slide back and forth in the rings. Creative use of weights may be in order, or the application of vibration suppression pads. I turned the motor back on, finding the need to track the Moon manually far more distracting than the slight jitter introduced by the motor.
Rima Ariadaeus was also nicely placed relative to the terminator. Accustomed as I have become to viewing rilles with the Newt's 8 inch mirror, I was pleasantly surprised by how clearly the details of Rima Ariadaeus could be seen. I was able to trace its length from the crater of the same name, westward to just short of where it approached Rima Hyginus. The rille was especially visible along its middle third, centered on the place where it crosses the north-south ridge that skirts the west wall of crater Silberschlag. All along its visible length it gave the impression of a shallow groove, with some idea of actual depth being noticeable in that middle portion. It seemed to begin full-blown at its eastern end, deepen near Silberschlag, then gradually fade away as it passed into the west.
Encouraged by Ralph's performance, I shifted my attention to the rille system around Triesnecker. This time I was disappointed, able to see only the angle of the main rille near the crater. In steady moments I thought I could see other portions, thin and spidery tracings on the surface of the Moon, but the combination of lighting and seeing conditions made it impossible to make a proper observation. This held true when I pushed the magnification by trying various eyepieces with the 2x Barlow. I decided to come back to this on a night when conditions support somewhat higher magnification.
The crater Julius Caesar always makes me think of the mark of a thumb placed carelessly on a charcoal sketch. It has that kind of smeared quality. If what is believed of the geology of the region is in fact true, the flow of debris from the Imbrium impact is responsible for this effect, and for much of the character of the landscape around Julius Caesar. The crater, its neighbors, and all the features around it seem to have been scraped or stretched from northwest to south east. Julius Caesar has a worn and beaten look to it and its rim northwest and southeast of the crater's center, barely rises from the surrounding landscape (an effect especially visible around the southeastern portion). It is easy to imaging a titanic debris flow running roughshod over the region. Tonight the thickish western rim of the crater (more a curved mound of rock than a crater rim, from the looks of it) played an interesting trick of the light. I'm speaking of the rim as it runs from J. Caesar A to J. Caesar B. Craterlet A was not especially prominent, but the main crater wall was well and brightly lit, describing a chubby curve that ended in a slightly broader portion containing shadow filled Cassini B and Cassini J. The interplay of light and shadow created a peculiar illusion, of a bright, curved body ending in a somewhat triangular head containing two black eyes (B and J). It took a moment for the animal shaped by these lights and shadows to swim in from childhood memories; I was looking at a tadpole! A giant tadpole on the Moon!
I wonder what the neighbors thought of the quiet laughter that floated out of my back yard tonight?
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04/05/2008, Farnsworth Ranch, AZ
Seeing: P. 4
Transparency: (NELM) 6.0 (SQM) 21.55 at 10:16pm MST and 21.65 at midnight.
Weather: occasional light breeze, warm at the start (low 80s F) dropping to the low 60s by midnight.
Instrument: SVP8EQ
Eyepiece/filter list: 21mm Stratus, 5mm Stratus, 32mm Agena SWA, 9.5mm Lanthanum, 25mm Sirius Plossl, 10mm Sirius Plossl, 2x Barlow, 4mm UO Orthoscopic, Paracorr.
Time for the annual All Arizona Messier Marathon. I attended, but this year decided to use the time under dark skies for observing, and let others run the marathon. As a result I was able to spend a relaxing evening with friends while making significant progress on the AL Messier Club project. I also wanted to take care of some AL double stars, but when it turned out the seeing conditions were not the best for double star observing, I elected to skip those objects and focus my energy on the Messier portion of the list. As a result I was able to observe (in most cases, re-observe) seven Messier objects and produce credible sketches.
I arrived later than intended and found Ron, Jim, and a guy named David crowded into the shade of the back hatch of Ron's SUV. The plan was to set up the Big Top and provide shade for the early arrivals, but the west wind that kicked up that afternoon made it impossible to do so, and we just made do with the shade of vehicle. Fortunately, though it was a bit on the warm side, it was not uncomfortably so; the wind had that benefit, at least. The wind was a seriously mixed blessing, since in addition to knocking down shades erected earlier in the day and flattening a tent or two, it spawned some powerful dust devils when wind met updrafts. One of these upended an 11 inch SCT and left it in pretty bad shape. (The owner packed up the damaged telescope and drove off shortly after I arrived. I can't begin to imagine how bad he must have felt on the long drive home.)
The afternoon dragged but there was enough conversation to divert us until the sun settled low in the west and the wind, mercifully in keeping with the predictions, dropped to a gentle breeze. (Later in the night it would become no more than a fitful whisper out of the south.) There was the usual sunset gathering and instruction session, showing a smaller crowd than last year's marathon. Apparently the fact that it would not be possible to see all of the Messier objects this year put some folks off, although the (unfortunately accurately predicted) seeing conditions and the constantly rising price of fuel could not have helped. (The number of attendees has not yet been posted on the SAC website as I type these words.) With the lecture completed the crowd dispersed, and a night of star gazing began.
I was anxious to nail down one object in particular as soon as it was dark, since M79 in Lepus was about to disappear into the sunset for the season - again. While I waited I scanned the sky with binoculars and enjoyed the peaceful process by which the sky darkens and the stars begin to appear, a few bright ones here and there, at first, then in rapidly swelling legions. Fragments of conversation drifted through the air as marathoners started gearing up and searched for objects made elusive by twilight, but that would not be found if they waited for complete darkness. As usual, the only clouds in the sky were in the low northwest quarter of the sky in which M31, 32, and 33 are to be found. The oft repeated refrain of "Got it yet?" was usually followed by a vexed denial. A bit past 8pm the sky was dark enough to do M79 justice, and I got started.
M79 was a quick find, mostly because this is not the first time I've tracked it down. I used the 25mm Plossl as a finder eyepiece at this point, and in it this globular cluster formed a faint, fuzzy ball in a fairly busy star field. Working from past experience I went straight to the 5mm Stratus, an eyepiece that usually works very well on globular clusters. In it M79 dominated the center of the field, a globe of hazy light that faded away into the sky with edges that were difficult to discern. As usual the sketch I made exaggerated this "edge effect," although having learned to use a blending stump for sketching such an object, the exaggeration is not nearly as pronounced as in my earlier sketches of globs and galaxies. This one technique, by itself, has made my copy of Astronomical Sketching a worthwhile investment. The glow of M79 is pretty uniform, with only a hint of a central condensation. In the past I've though I could see a bit of graininess to the cluster, that hint of stars on the edge of resolution. Low elevation and poor seeing probably conspired to prevent such an observation this time.
Jim started making "Oh, wow," comments, and when I asked what was up (realizing as I asked that he was not using his big dob) he pointed out the zodiacal light rising up out of the west, with the Pleiades embedded near the apex. The best way to describe the soft glow, quite clearly visible, would be to image the ghost of the Milky Way seen from a site not quite dark enough. A beautiful sight to contemplate, and thanks to Jim for pointing it out.
I wanted to take on M1 next, but it was not quite dark enough at that point (I thought) to get a good look. (The look I had at this point turned out to be as good as it was going to get.) While waiting, I decided to have some fun with the new 2 inch eyepiece and the Paracorr. I'd just seen a great view of M42 through Ron's big SCT, and put the same object in the new eyepiece/Paracorr combo so we could compare views. No direct comparison could be made (of course) due to different aperture sizes, but the differences in view between the two scopes was edifying. Curious about how the Newt performed, Ron brought several wide field eyepieces over, and we experimented. I did not take note of all of the examples, but two stand out. First was the William Optics 33mm UWAN, the performance of which was (to my eye) identical to the 32mm Agena SWA. I'm not familiar with the William Optic eyepiece line, but Ron seemed surprised by my reaction. The other outstanding memory of the brief eyepiece swap was the 28mm Pentax XL, which gave (in the Paracorr, at least) the finest view of the Great Nebula the Newt has ever provided. I'd put that eyepiece on my wish list, but they are apparently no longer in production these days, and on the used market seem to be as rare as the proverbial hen's teeth. I fully expect that, when I do find one, the price will not make me happy.
At last I decided to observe and sketch M1, making careful use of a blending stump, yet again. Even under fairly dark skies, this object is at best subtle, the faint fuzzy of faint fuzzies. After swapping eyepieces in and out, I settled on the old 17mm Celestron SMA, not so much because it gave a superior view but because adding magnification didn't get me anywhere. In tonight's view is was a fairly uniform glow that faded gradually and a bit raggedly into the sky around it. It's easy to see where Messier might have gotten his false comet idea from this object.
It was at this point that I discovered the seeing conditions would not support most of the double stars on my list. I gave a couple of these a try, and decided to concentrate my time under dark skies on the Messier objects instead.
The next Messier object I attempted was M93, which was by then also getting a bit low in the southwest. From past experience I knew this object could be spotted in binoculars, so with a suitable chart under the red light, started scanning Puppis. In my first sweep, just as I realized I was pointing the binoculars a bit too far south and east, a round gray patch caught my eye. I noted its location and, checking the atlas, realized I had accidentally "discovered" NGC 2451. In the Newt, using the 21mm Stratus, it was a wide scatter of more than a dozen stars, many distinctly yellow or blue, and one prominent star (C Puppis according to NSOG) that was orange. It was an unexpected pleasure, and a beautiful diversion. In a few more minutes I'd tracked down and had in view M93, a much less colorful gathering of a couple dozen stars, arranged in pairs, trios, and quartets. The cluster was set in a fairly busy field of view. I ended up sketching it in the 25mm Sirius Plossl, stuck into a 2x Barlow.
Sketching open star clusters can be a time consuming process, and by the time I was done with my rendering of M93 it was nearly 10pm. The decision to blow off the double star list was proving to be a good one. M50 was up next, another loose open cluster with a mix of a few (maybe 10) brighter and numerous fainter stars. There was a triangular asterism that seemed to dominate my impression of the cluster, and what had the appearance of a double star to the north, one member of which was distinctly reddish. This cluster was unusual tonight in that I have not observed it before, quick looks during Messier Marathons notwithstanding. As a result, I spent a significant amount of time looking at and sketching M50, time well spent as this is a very attractive star cluster. The 25mm Plossl did this one justice.
After a little time walking around and visiting the neighbors to help clear my head (it was past 11pm by this point) I next tracked down M48. This is another bright and beautiful open cluster, a characteristic shared by many Messier open star clusters. I used the 21mm Stratus on this one, and made a sketch that probably did not do the busy star field of the cluster justice. The west side of the cluster seemed to me to be more concentrated, with stars arranged in looping chains that seemed to open up somewhat to the east. This was another time consuming sketch, and at some point I made an arbitrary decisions to stop plotting ever fainter stars.
Midnight came and went. I took another break, refueled, and visited some more with the neighbors. When I went back to "work" I tracked down my only galaxy for the night, M106. Using the 21mm Stratus as a finder eyepiece, and starting my star hop with beta Canes Venatici, I made another accidental "discovery" when I found the galaxy pairing of NGC 4485 and 4490. A quick look with the 9.5mm Lanthanum verified what I was seeing, but I did not linger. It took a while to find M106, an indication that I was wearing down and coming up on the end point of the observing session. But I did find M106 and sketched it, still using the 9.5mm Lanthanum. This galaxy was elongated north to south, with a gentle brightening near the core. This object, also, was one I have not previously observed, so I lingered over it, not starting to sketch it immediately, contemplating its enormity and distance. Galaxies always have this effect on me, and when the night is growing longer and I've started to wear down, it grows easier to fall into reverie and stay there for a time. M106 ended up being the sight, through the Newt, that appeared behind my eyelids when I finally gave in to the need for sleep.
Which I was not quite ready to do, not just then. Saturn was high in the night, and seeing conditions or no, I felt a need to pay my respects. It was not the best view I've ever had of this world, so much closer that M106 that it almost seemed cozy. But in moments of fleeting calm I could glimpse (using the 4mm UO orthoscopic) the Cassini division, polar duskiness, and the spark of Titan. A poor view of Saturn beats not looking.
It was pushing 1pm, and memory prompted me to scan the low south with the binoculars, seeking and finding Omega Centauri. I was curious to see what the Paracorr/21mm Stratus combination would make of this globular cluster. I was not at all disappointed. Seeing conditions were not an issue here, so low in the sky; you expect it to be pretty poor. In fact, the view was steadier than I expected. The cluster was diffuse grey ball that faded into the sky around it in that tattered fashion you can sometimes see with globulars. Across the surface there was a graininess, almost having the quality of a texture. Omega Centauri filled the central third of the field of view, more or less. I only rarely have the chance to glimpse this one, and it isn't something I pass up, a sentiment shared by Ken, who was set up just to the south. He was running the Marathon, but had taken a moment away from it to do as I had just done, and invited me to have a look at Omega Centauri through his 16 inch dob. That's not an opportunity to be passed up either. With the greater resolving power of the big dob, what in the Newt appeared as a slight grittiness on the surface became the glitter of stars resolved, or just on the edge of it. An amazing thing to see in the first hour of a Sunday morning.
The view of Omega Centauri through a 16 inch telescope woke me up enough the I decided to go for one more Messier object, M68. Proof that I really wasn't as awake as the view through the big dob made me feel came when I found it difficult to hop to this more distant globular cluster, but I finally managed to find it. (Especially frustrating, since this is one of those Messier objects I've observed but not sketched in the past.) Unlike M79 at the start of the night, M68 has the appearance of structure, with a brighter core and distinct halo. There was no sign of stars resolving in the face of the object, but I could just make out the irregularities that other observers report as mottling or dark lanes. To my eye the cluster was not completely round. I used the 9.5mm Lanthanum to sketch this one.
With M68 my night came to an end. Carter and Ken were still working their way through the marathon, but I had accomplished just enough by this point that pushing it seemed difficult to justify. It had been a busy day just getting to the marathon site. It all caught up with me, and I decided not to fight it. Usually I crawl into the Subaru with reluctance, not wanting the night to end, but this time it felt like the right thing to do. I woke shortly before dawn, with a pearl grey glow in the east and Jupiter shining like a silver beacon in the southern sky. Marathoners were drifting around the field, comparing notes and offering congratulations to those with impressive numbers. I felt rested, though desperate for a cup of coffee. I packed it up, made my farewells to the marathon stalwarts, then headed into Arizona City to join Ron for breakfast (coffee!) and a good long talk. A better way to end a star party would be hard to imagine.
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